This invention relates to punch and binding machines, and more specifically, to mechanisms for cooperatively gauging the thickness of material to be punched and adjusting the punching mechanism in accordance therewith.
Punch and binding machines are used for punching binding apertures in paper or text material and covers, and thereafter binding the punched materials with a binder element of the type having a backbone and curled binding fingers so as to form a book, chart or the like. The binding mechanism opens or uncurls the binder element fingers so that the punched material may be impaled thereon at the binding apertures, and then bound when the fingers are released and recurl. Combined punch and binding machines are shown in U.S. Pat. Nos. 3,122,761; 3,125,887; 3,227,023 and 3,793,660. Binder elements are shown in U.S. Pat. No. 1,970,285.
In practice, different sized or diameter binder elements are used to bind different thicknesses of paper or other material. For example, binder elements are available in 3/16-, 1/2-, 1- and 2-inch diameter sizes. It has been found that along the bound edge, the distance between the edge and the binding aperture (edge/aperture dimension) should be adjusted for different thicknesses of material being bound. More specifically, the edge/aperture dimension should increase as the thickness of bound material increases. Thus the edge/aperture dimension is less for material 3/16" of an inch thick than for one inch of material.
In the prior punch and binding machines, there is no provision for measuring material thickness and directly relating that thickness to the edge/aperture dimension. Furthermore, in such machines the edge/aperture dimension is determined by an adjustable back gauge plate. In U.S. Pat. No. 3,793,660, the position of that plate is adjustable in relation to the selected binder size by a gear-type mechanism. However, it has been determined to be desirable to eliminate the rotary positioning mechanism.
It is therefore an object of this invention to provide a thickness measuring device in association with a punch and binding machine.
It is another object of this invention to provide a back gauge plate positioning device cooperatively associated with said thickness measuring device.
It is a further object of this invention to provide a non-gear back plate adjustment mechanism.
These and other objects of this invention will become apparent from the following description and appended claims.